<template>
  <div class="goods">
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li 
          v-for="(item, index) in goods" 
          :key="index"
          class="menu-item" 
          :class="{'current':currentIndex===index}" 
          @click="selectMenu(index, $event)"
          ref="menuItem"
        >
          <span class="text border-1px">
            <span v-show="item.type>0" class="icon" :class="classMap[item.type]">
            </span>{{item.name}}
          </span>
        </li>
      </ul>
    </div>
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li 
          v-for="(item,index) in goods" 
          :key="index"
          class="food-list" 
          ref="foodList"
        >
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li 
              @click="selectFood(food, $event)" 
              v-for="(food, index) in item.foods"
              :key="index" 
              class="food-item border-1px"
            >
              <div class="icon">
                <img width="57" height="57" :src="food.icon">
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span>
                  <span>好评率{{food.rating}}%</span>
                </div>
                <div class="price">
                  <span class="now">￥{{food.price}}</span>
                  <span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cart-control @add="addFood" :food="food"></cart-control>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <shop-cart 
      ref="shopcart"
      :select-foods="selectFoods"
      :delivery-price="seller.deliveryPrice"
      :min-price="seller.minPrice"
    >
    </shop-cart>
    <food @add="addFood" :food="selectedFood" ref="food"></food>
  </div>
</template>
<script>
  import { getGoods } from '@/api/index.js'
  import Bscroll from 'better-scroll'
  import ShopCart from './components/ShopCart'
  import CartControl from './components/CartControl'
  import Food from './components/Food'

  export default {
    name: 'Good',
    components: {
      ShopCart,
      CartControl,
      Food
    },
    props: {
      seller: {
        type: Object
      }
    },
    data() {
      return {
        goods: [],
        scrollY: 0,
        listHeight: [],
        selectedFood: {}
      }
    },
    computed: {
      currentIndex() {
        for (let i = 0; i < this.listHeight.length; i++) {
          let height1 = this.listHeight[i];
          let height2 = this.listHeight[i + 1];
          if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
            return i;
          }
        }
        return 0;
      },
      selectFoods() {
        let foods = [];
        this.goods.forEach((good) => {
          good.foods.forEach((food) => {
            if (food.count) {
              foods.push(food);
            }
          });
        });
        return foods;
      }
    },
    created() {
      this.classMap =  ['decrease', 'discount', 'special', 'invoice', 'guarantee'],
      getGoods().then((goods) => {
        this.goods = goods
        this.$nextTick(() => {
          this._initScroll()
          this._calculateHeight()
        })
      })
    },
    methods: {
      selectMenu(index, event) {
        if (!event._constructed) {
          return;
        }
        let foodList = this.$refs.foodList;
        let el = foodList[index];
        this.foodsScroll.scrollToElement(el, 300);
      },
      selectFood(food, event) {
        if (!event._constructed) {
          return;
        }
        this.selectedFood = food;
        this.$refs.food.show();
      },
      addFood(target) {
        this._drop(target);
      },
      _drop(target) {
        // 体验优化,异步执行下落动画
        this.$nextTick(() => {
          this.$refs.shopcart.drop(target);
        })
      },

      // _getGoods() {
      //   getGoods().then((goods) => {
      //     this.goods = goods
      //   })
      // },
      _initScroll() {
        this.menuScroll = new Bscroll(this.$refs.menuWrapper, {
          click: true
        })
        this.foodsScroll = new Bscroll(this.$refs.foodsWrapper, {
          click: true,
          probeType: 3
        })

        this.foodsScroll.on('scroll', (pos) => {
          if (pos.y <= 0) {
            this.scrollY = Math.abs(Math.round(pos.y));
          }
        })
      },
      _calculateHeight() {
        let foodList = this.$refs.foodList
        let height = 0
        this.listHeight.push(height)
        for (let i = 0; i < foodList.length; i++) {
          let item = foodList[i]
          height += item.clientHeight
          this.listHeight.push(height)
        }
      }
    }

  }
</script>
<style lang="stylus" scoped>
  @import '~@/assets/stylus/mixins.styl'

  .goods
    display: flex
    position: absolute
    top: 174px
    bottom: 46px
    width: 100%
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height: 54px
        width: 56px
        padding: 0 12px
        text-align: center
        line-height: 14px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          font-weight: 700
          background: #fff
          .text
            border-none()
        .icon
          display: inline-block
          width: 12px
          height: 12px
          margin-right: 2px
          vertical-align: top
          background-size: 12px 12px
          background-repeat: no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          font-size: 12px
          border-1px(rgba(7, 17, 27, .2))
    
    .foods-wrapper
      flex:1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147, 153, 159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7, 17, 27)
          .desc, .extra
            line-height: 10px
            font-size: 10px
            color: rgb(147, 153, 159)
          .desc
            margin-bottom: 8px
            line-height: 12px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240, 20, 20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147, 153, 159)
          .cartcontrol-wrapper
              position: absolute
              right: 0
              bottom: 12px

</style>